Collapsible joint for drill stems



Oct. 18, 1932. G. v. POWERS COLLAPSIBLE JOINT F08 DRILL STEiIlS FIG.I.V

Patented Oct. 18, 1932 UNITED STATES- GEORGE v. rownns, or OKLAHOMA crrY, oxranorra COLLAPSIBLE JOINT FOR DRILL STEMS Application filed September 18, 1930. Serial No. 482,696.

My invention relates to drill stem joints and more particularly to a joint which may be collapsed when the drill bit becomes stuck in the hole.

The objects of my invention are to provide a device of this class which is new, novel, practical and of utility; which will be placed in the drilling column between the lowest joint of drill stem and the upper end of the drill collar; which may be connected within the drill stem by usual stem boxes and pins; which will function in the drill stem without weakening such stem during the drilling operation; which will permit the drill stem to be disconnected from the drill collar should the bit become stuck in the well; which will be simple in installation and comparatively cheap in manufacture; which will be strong and durable; and, which will be efficient in accomplishing all the purposes for which it is intended.

At the present time in rotary drilling when the drill bit becomes wedged or stuck in the bore hole, it is necessary to sever the stem from the drill collar. This is usually accomplished by cutting the stem at a point above the drill collar, or by exploding an explosive at apoint adjacent and above the drill collar sufficiently strong to sever the stem. The first method requires special equipment which is expensive and which requires considerable time .in its operation. The second method often dislocates the drill bit and collar from its position in the well which makes it diificult and at times impossible to again connect upon the drill collar to withdraw the bit.

My device is designed in a manner making it possible to quickly disconnect the stem from the drill collar without in any manner dislocating or changing the position :of the drill bit or collar. After the stem has been removed from the drill collar, it is then possible to hydraulically dislodge the bit from its congested position.

With these and other objects .in view 'as will more fully appear, my inventionconsists in the construction, novel features, and combination of parts hereinafter more fully described, pointed out in theclairns hereto appended, and illustrated in the accompany mg one-sheet drawing, of which: 7 v The figure is a vertical sectional view of the device. 7 I I iv Like characters ofreference designate like parts in the figure.

It is understood that various changes in the form, proportion, size, shape, weight and other details of construction, .within the scope of my invention may be resorted to without departing from the spirit or broad pr nclple of my invention and without sacrificing any of the advantages thereof; and it is also understood that the drawing is to be interpreted as being illustrative and not restrictive.

One practical embodiment of the invention as illustrated in the drawing is: V i V A hollow cylindrical coupling 1 having ex terior right hand tapered threads 2 and 3, 7

which are adapted to fit within a usual drill stem coupling pin or box, not shown. Within the upper portion of the body of said coupllng are provided a plurality of rectangular longitudinal grooves which are filled with 7 some soft metal such as lead, babbitt'or the like formlng soft plugs 41, The upper portion of the bore 5 of said coupling 1 is slightly tapered inwardly as shown at .6. Within said tapered portion 6 is provided a hollow cylindrical plug having ,a bore 8 and having its upper exterlor portion tapered to jconform to the tapered portion -6 of said coupling 1.

pling 1 is slightly smaller than'its body and forms a shoulder 9,.above which are provided exterior threads 10. Said plug 7 acts as a means for reinforcing the upper portion of said coupling 1 where-it'has been weakened by the provision of said soft plugs 4. As, a

means of rigidly holdingsaidplug 7 inplace within saidcoupling 1, VI provid ing Said ring 11 is preferably madeofainetal such as brass or-the like, slightly softer than we the metal used in making said coupling 1 and said plug 7.

In order that the threads 12 on the exterior of said ring 11 may conform exactly to and form a continuation of threads 2 on coupling 1, it has been found desirable to first install ring 11 upon threads 10 of plug 7 and to then cut the threads 12 and 2 in one operation.

Operation When the drill bit becomes wedged or stuck in the hole and it is desired to disconnect the stem from the drill collar, a pointed weight will be lowered through the stem to a point slightly above the top of ring 11 and will then be dropped upon said ring 11 with suificient force to shear the threads upon the interior of ring 11, thus dropping plug 7 downwardly through said coupling 1. The removal of said plug 7 which has previously reinforced the upper portion of said coupling 1 at the point at which said soft plugs 4 occur, will so weaken the upper port-ion of said coupling 1 that the rotation of the drill stem towards the right will collapse the upper portion of coupling 1. This will be made comparatively easy by the presence of said soft plugs 4. It may, of course, be understood that the coupling box into which said threads 12 and 2 are threaded will extend slightly downward past the lower ends of said soft plugs 4 and will-be threaded upon some 3 rd full threads on said. coupling 1. These 3 or 4 threads will be stripped when the stem is rotated due to the fact that the upper surface of ring 11 will contactthe usual shoulder within said coupling box. Wlienthis has occurred the drill stem will have been severed from its connection with coupling 1 and may be withdrawn from the hole.

Obviously, the invention is susceptible of embodiment in forms other than that which is illustrated in the accompanying drawing and described herein, and applicable for uses and purposes other than as detailed, and I therefore consider as my own all such modifications and adaptations and other uses of the form of the device herein described as fairly fall within the scope of my invention.

Having thus described my invention, what is claimed and desired to be secured by Letters Patent, is: V r

1. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a weakened portion of said pipe section, and removable means for normally reinforcing said weakened portion.

2. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a weakened portion of said pipe section, removable means for normally reinforcing said weakened portion, and means for holding said reinforcing means in position.

3. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a weakened upper portion of said pipe section, removable means for normally reinforcing said weakened portion, and means for holding said reinforcing means in position.

4. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a plurality of openings formed longitudinally in the upper portion ofsaid pipe section for weakening that portion, removable means for reinforcing said weakened portion, and means for holding said reinforcing means in position.

5. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a plurality of openings formed longitudinally in the upper portion of said pipe section for weakening that por-' tion, a seml-soft removable material within said openings for reinforcing said weakened portion, a hollow, removable reinforcing member within said weakened portion, and breakable means for hOldiIlg said reinforcing member in position.

6. A drill stem joint comprising a pipe section adapted to-be connected between sections of a drilling column, a plurality of lon gitudinal slotsin the upper portion of said pipe section for weakening that portion, soft metal filters within said slots, a removable hollow core adapted to be inserted in the bore of said pipe section within its weakened'portion for strengthening said portion, and means for holding said core in position.

7 A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a plurality of slots formed longitudinally in the upper portion of said pipe section for weakening that portion, a soft metal filter for each slot, a hollow'removable core adapted to be inserted in the bore of said pipe section within its weakened portion for strengthening said portion, and breakable means for holding said core in position. V

8. A drill stem-joint comprising a pipe section adapted to be connected between sections of a drilling column, a plurality of slots formed longitudinally in the upper portion of said pipe section for weakening that portion, a soft metal filler within each slot, a hollow removable core adapted to be inserted in the bore of said pipe section within its weakened portion for strengthening the. said weakened portion, and a ring of soft metal for holding said core in-its reinforcing position.

9. A drill stem joint comprising a strong metal pipesection adapted to be threadedly connected between a drill collar and the lowermost section of'a drill stem, the bore of said pipe sectionfor the entire thickness of said per end, a plurality of spaced slots formed longitudinally inthe' upper portion of said pipe section tapered inwardly toward its up- I [in pipe sections wall, a soft metal filler within each slot for reinforcing said upper portion, a hollow core adapted to be inserted within and tapered to fit the bore of said pipe section within its weakened portion, said core having a threaded portion extending slightly above the upper end of said pipe section and adapted to normally reinforce said weakened portion, and a ring of breakable metal threaded upon said extending portion for holding said core in its reinforcing position.

10. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, weakened portions on said pipe section, and removable means for normally reinforcing said weakened portions.

11. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, a plurality of Iongitudinal slots formed in the upper portion of said pipe section for weakening that portion, soft metal fillers in said slots, a removable hollow core inserted in the bore of said pipe section within its weakened portion for strengthening said portion, and frangible means for holding said core in position.

12. A drill stem joint comprising a pipe section adapted to be connected between sections of a drilling column, said section having a plurality of longitudinal slots formed in its upper portion for weakening that portion, soft metal fillers in said slots, a removable hollow core inserted in the bore of said pipe section within its weakened portion for strengthening said portion, and frangible means for holding said core in position.

GEORGE V. POWERS 

